I do not think it's basically the chipset that's causing problems. It is more of an impedance problem. My USB cables for the tethering are all 5m - 10m long. Using shorter cables in the studio makes no sense to me. To my knowledge there is a length specification for USB 3 of max. 5 m. But there are many supposedly good cables that are 3 m long, no longer within the parameters.

But that's not just the fault of the cable. Transmitter and receiver automatically and dynamically match your transmit power and frequency characteristics. Without such tricks, signals of up to 5 GHz could not be transported over cheap cables and plugs.

Battery powered cameras usually do not have such a good transmission power. For some of my cameras, the transmit power gets a bit better with a continuous power supply. The 645Z is not part of my feeling.

Some applications are sensitive to such problems, while other applications simply repeat the transfer.

Greeting Gerd

PS: Please do not cascade if possible USB Repeater / HBS that often leads to new problems.

The LS lenses can be an alternative (I use them occasionally), but it depends on what is required. For example, Can you with 1/500s with aperture open not really against the sun flashing.

That's right.

But I also use the 67mm SMC Pentax 105mm F2.4 which is a very nice portrait lens. Or even a Hasselblad 110mm F2. Since the 645Z refuses the TTL function, because the aperture is missing. And I can not work with HSS or SuperSync.

The D810 is a power at ISO 64 in the studio. But with higher ISO performance it has nothing to counter the 645Z and the GFX. You can see the difference as from ISO 800. It remains to be seen where the D850 of the ISO performance will actually stand. You should also consider the PixelPitch. The D810 has a pixel pitch of 4.87 μm. The new D850 should have a PixelPitch of 4.35 μm (Sony A 7 RII of 4.5 μm). This will make it the D850 not really easy to make very good high ISO achievements. I would be glad if it would be on the level of the D810. For comparison the 645Z / GFX have a PixelPitch of 5.32 μm. If you want to have really good picture quality, the small pixels of the D850 also restrict the choice of lenses at Nikon.

Subject. Flash:
The 645z has fewer possibilities/performance with the flash than the Fuji GFX and the D810 (D850 presumably synonymous). The new lightning triggers have enabled the 645z a lot, but unfortunately there are many deficits. For example - the 645Z can not easily flash on the second curtain (this is annoying at moving images in many situations). The 645Z tries to calculate the flash power with a TTL device (which is necessary for HSS and SuperSync). For this purpose, it requires minimal aperture, shutter speed, and distance measurement. If one of these factors is missing, the 645Z will stop the flash. What the case is with manual lenses without aperture transmission. The GFX does not. It always triggers TTL even if the aperture value is missing. And it also triggers the flash "always" without TTL device. That goes with me to 1/160s without which a shading or a curtain in the picture is to be seen. The manufacturer/flash support is unfortunately with Nikon and Fuji significantly better. What I find very bad, but Pentax itself has since made no decisive step.

I can not draw a clear summary.
In the studio (almost) 100% decides the light I set. The differences between the formats/cameras are then only to be seen, if one knows exactly what one must pay attention. The situation is different in ambient light or mixed light. Since the 645Z and the GFX are in my opinion clearly advantage. The tonal values are however the small medium format cameras - with me - always better as well as the details. I use the GFX with all Pentax 67/645 lenses as well as many Mamiya RZ / RB / 645 lenses. The camera lens combinations deliver excellent results. But clearly with the reference in the GFX (with the Pentax / Mamiya lenses) at the time without AF.

the blurred light edges on the feet are correct. The light beam is created by your backlight (which is already slightly outshone) and the blurred by the motion blur.

With techniques such as HSS or SuperSync, PowerSync etc. you can not freeze fast movements by "LIGHT". You can shoot with such techniques only over the shutter speed a picture absolutely sharp. Both techniques produce only one kind of continuous light.

Another possibility is to expose the subject only via the flash time of the flash. Then, however, the flash must be correspondingly fast and the ambient light must not play any role. If you only over the burning time exposes, you can the 645Z synonymous to 1 / 125s pose and the picture is still sharp.

Focus by Wire is indeed a problem. The 63mm for the GFX has engine problems when installing a simple 100mm Gradient filter with holder (Lee). The GFX gives an error and the lens no longer works. Manually focus is then also turned off because the focus is by wire. Gone stupid...

I use the D FA 25mm on the GFX. Together with a small Cambo Actus I can then also make Tilt / Shift and Swing (weight of Actus ca. ~ 1kg). Cambo can control 645 lenses without aperture ring. The adjustment paths with a full 645er lens are more than sufficient and I'm quite happy with it ...

that's right. Also the Huelight profiles and other profiles, which I also use, move in most cases the WB.

Greeting Gerd

---------- Post added 03-05-17 at 03:17 AM ----------

Hello Paulster,

the standard Adobe profile or the embedded profile, but if the camera is set to neutral, the WB in Lightroom may not be allowed to move this.
The manufacturer production tools such as Capture NX for Nikon or also Digital Camera Utility for Pentax do not do that either. In these tools exactly the WB is displayed which I have adjusted in the camera - on the Kelvin exactly.

What is conspicuous is: If I set fixed WB profiles in the camera such as Daylight, Cloudy etc .. then the deviations in LR is not so strong. If I adjust manual values in kelvin - and I do almost always - then the deviations in LR are in part considerable.

Of course this is not a broken leg, because you can always influence the WB - in the RAW file - in 100%. But if Adobe writes to the controller a value - like Kelvin - and that's not true. Then they should write to the controller only "for fun".

Alternatively, a manual entry would be appropriate why and how the WB value in Adobe products is composed. Then all can handle it.

Greeting Gerd

---------- Post added 03-05-17 at 03:34 AM ----------

Supplement - I had just forgotten on the subject WB in LR:

For example, if the kelvin value is "as shoot" equal to 5400K - then LR does not sync 5400K between different photos but only the value "as shoot". You have to change the value to 5401K and then the kelvin value and not the value "as shoot" will be synchronized.

That have all the cameras - not only the 645Z. The problem is that each camera has different differences. Even from the Nikon D750 to the D810 the difference values are very differently large. This makes it difficult to synchronize the WB when photographed at one event with two different cameras.

@BOB L

I have tested with the adobe standard profile. The embedded differ slightly from Adobe standard profile - from me.

The menu option 11 point 3 (flash) means that the WB is not measured until the flash is triggered. It does not mean that the White Balance is set to flash (5400 K). Depending on the light set, ambient light is always present. How much can you easily measure with an external exposure meter. Correctly point 4 would be unchanged and then make the WB over the normal WB selection.

JPEGs do not contain WB / Kelvin values. Lightroom provided for RAW's basically wrong values, with every camera I know.

You can easily check this:
Take an exposure series with the 645Z. Specify the Kelvin value manually. For example starting with 5000k in 300k steps to 5900k.

The result looks like this:
645Z................LR
5000K..............5350K
5300K..............5650K
5600K..............6000K
5900K..............6350K

The value in LR drifts, but not at the same distance. There is no fixed conversion value. This makes LR different for each camera. My D810 drifts differently than my A7RII and the 645Z.

I've noticed because one had photographed with two cameras and I wanted to balance the WB. The results were very different. Logically when 5600K on the D810 is not also 5600K at the A7RII or the 645Z - in Lightroom - are.

There are things like ...
- In the case of flash lighting, the white balance only works in the Auto and Underwater modes.
- The electronic shutter can not be used with a flash (not at all).
- There are no presets you can save.
Etc...

Alone that I have in the league with the flashing only a auto WB is completely indiscutable.
I remember the Fuji (currently) to a Playstation. My 645Z is in contrast a solid tool.

There are pictures of the Fuji in full resolution as RAW + JPEG with the 63er published.

I work almost exclusively with sketches in the product or still life photography. Either it is own sketches or one gets them from the advertising agencies, which must then also be implemented the same. Often, ideas come when one sees certain objects or situation. I then write these things into my personal sketchbook to convert them somehow or other similar.

A still life translation from my sketchbook, with the aim of letting a necklace float in unusual light. It should not be an realistic take-up, e.g. To work out the materials.

For image composition:
The necklace hangs on a transparent thread on the brooch on the head. This is mandatory because otherwise the chain itself can not float without help in the bow. This means the picture is actually photographed on its head. The background brightness is generated by an optical narrow beam. Standing upside down - from the right a stripped stripelight and from the left a brightener with mirror foil which is glued to cardboard. The Flairs were created with a pot scratch, which I put into the lens, and brought to the side from below with a snoot to light up. The star arises from vaseline, on a glass disk in star shape, through which I photographed. I had to work on the EBV in the reflection, however, because I did not pass the vaseline precisely enough. Finally, the camera set to 3800 Kelvin to get the cool color mood.

Various remote triggers but behave differently with me. If the 645Z recognizes a P-TTL compatible device (remote trigger) without aperture transmission from the lens, then I can set the shutter speed for some remote triggers not over 1 / 125s. This can be done with other remote triggers, but the flash does not trip. But the result is the same.

I check it over the weekend, but I think I come to the same conclusion:

With pure TTL flashing with the flash on the camera (no man needs) the flash power is automatically controlled by the camera.
For this purpose, the camera requires the distance (measures itself), the aperture, the exposure time and ISO. Perhaps the reflector position when one uses a system flash. If one of these parameters is missing, the flash power can not be calculated and controlled automatically. This is exactly where the problem will be.

The remote triggers of Priolite, Cactus, Yongnuo etc ... deceive the camera a TTL compatible device, catch the TTL signal, change it and send via TTL the commands to the receiver. TTL is therefore only used for control. If the camera but believes it is missing a parameter, it refuses the release.

I can guarantee you however if you use a simple remote trigger (without TTL) only with the middle contact, then it goes. Do you absolutely need shutter speeds with flash over 1 / 125s? In the studio, I'll fix this over the burning times of the flashes.

SuperSync (or HyperSync as Priolite calls it) is a completely different scenario. The transceiver requires a TTL protocol (P-TTL with Pentax) to ignite the extremely slow burning flash before the actual release. While the flash burns very slowly, usually with 1 / 100s, the slit curtain is moved over the sensor.

This means you move above the regular flash sync time of 1 / 125s. Since the cameras are sometimes problematic, if they mean something is missing. The problem will then remain within the flash sync time. As long as the camera recognizes a P-TTL flash and means there is something missing. Is the aperture of your 67 lens transferred to the camera?

I have never tried with SuperSync or HSS with an adapted lens above the flash sync time in the studio to work.

the 645Z will also release the flash without a lens - as long as you move in the flash sync time (just in the M or X mode).
I have the 645Z often at a Sinar P2 Fachkamera (which is like without a lens) and flashes wireless with several studioflashes. This works absolutely without problems.

For the 67 lenses I have two adapters from Fotodiox and K & F Concept on the 645 bayonet. Again, I have no restriction flash functionality.

Very strange problem what you have there. Perhaps a contact problem in hotshoe?

I think you have overlooked something essential. You can measure the white balance clearly on a gray map but you have to make it new for every light situation and every lens. In a backlight situation (sunset) this is likely to be difficult for you. A 100% white balance you only need with 100% color and the measurement is an 18% gray card still too little. Since you should use a color checker and create a 100% color profile for the respective light situation. But on the basis of your pictures, I see that you - until now - do not make reproductions.

But it is essentially only about the picture mood. Would you like to create a warm picture or rather a cooler picture? And that's what it's all about, what do you want to transport for a picture? And just after that you should choose the Kelvin value for the white balance.